Gelatin as a Fining Agent in Wine and Beer Production
A glass of wine owes much of its clarity and balance to a process invisible to the consumer. After fermentation, wine contains suspended particles - residual yeast cells, proteins, and polyphenols such as tannins - that cause haze, bitterness, and instability. Fining is the step that resolves this. Gelatin remains one of the most established fining agents in commercial winemaking.
What Is Fining and Why Does It Matter?
Fining is the addition of a reactive substance to juice or wine with the aim of removing components that compromise clarity, stability, or sensory quality.[1] These components do not always settle naturally. Left unchecked, they can cause protein haze during storage, shorten shelf life, or contribute to excess astringency and bitter finish.
The fining agent reacts with target compounds either chemically or physically, forming insoluble complexes that precipitate to the bottom of the vessel. The clarified liquid is then racked off. The choice of agent determines which compounds are removed, in what quantity, and with what effect on the final product.
How Gelatin Works as a Fining Agent
Gelatin is a protein derived from collagen, characterised by a high content of proline and hydroxyproline residues. Under typical wine pH conditions - usually between 3.0 and 4.0 - most commercial gelatins carry a net positive charge, which attracts negatively charged particles, above all tannins and other polyphenolic compounds.[2] The interaction occurs primarily through non-covalent forces: hydrophobic stacking of phenolic rings against proline residues, and hydrogen bonding between polyphenol hydroxyl groups and carbonyl groups linked to proline amino acids. Research on tannin-protein interactions in food systems confirms that proline-rich proteins such as gelatin show the highest susceptibility to tannin binding among common food proteins.[3]
Once bound, the gelatin-polyphenol complex becomes insoluble and flocculates. The combined mass settles to the bottom under gravity, and the wine above clarifies. This combination of electrostatic attraction and non-covalent binding distinguishes protein-based fining agents from inorganic agents such as bentonite, which operates differently and targets different fractions.
An important characteristic of gelatin is its selectivity. Research published in the American Journal of Enology and Viticulture found that gelatin preferentially removes larger condensed tannin fractions - the compounds most responsible for harsh, aggressive astringency - while leaving lower molecular weight fractions comparatively intact.[4] This selectivity makes it possible to soften a tannic wine without stripping it of all structure.
Gelatin in Winemaking: Red, White and Juice Applications
The Australian Wine Research Institute (AWRI), one of the leading applied research institutions in the wine sector, classifies gelatin as the most effective proteinaceous fining agent for tannin removal - ranking it first among all agents for this purpose - while noting it also ranks highly for colour removal and has the greatest tendency to overfine of all protein-based agents.[1]
- In red wines, gelatin is applied primarily to reduce excessive bitterness and astringency. Recommended dosage ranges from 30 to 240 mg/L depending on tannin load and wine style.[1] Younger, highly tannic wines may require higher rates; aged wines, where tannins have already polymerised into larger molecules, respond more dramatically to gelatin treatment because gelatin preferentially binds larger polyphenolic structures.[1]
- In white wines and juice, gelatin is used for clarification and reduction of phenolic compounds associated with browning and bitter aftertaste. Dosage range is narrower - typically 15 to 120 mg/L - because white wines contain fewer tannins and the risk of overfining is higher.[1] In low-tannin whites, gelatin is often used in combination with kieselsol (colloidal silica), a negatively charged agent that provides counter-fining and ensures complete precipitation of any residual gelatin protein.[5]
- At the juice stage, gelatin is occasionally added prior to fermentation to remove harsh phenolics from pressings. Some winemakers prefer this timing because the aromatic impact of fining is lower before fermentation than after.[5]
The Risk of Overfining
Gelatin's effectiveness is also its main risk. Excess dosage removes not only undesirable tannins but also protective colloids and colour compounds, leaving the wine thin in body and pale in colour. Industry guidance generally recommends bench trials before cellar application, using the minimum effective dosage.[1] The AWRI recommends always running a control sample without fining to evaluate the sensory effect of any addition.
Gelatin in Beer: Haze Removal After Fermentation
Beer haze forms through a different mechanism than wine turbidity. In brewing, haze is caused primarily by cross-linking between haze-active (HA) proteins - mostly from malt - and haze-active polyphenols from hops and malt husks.[6] These protein-polyphenol complexes become visible at cold temperatures as chill haze, and over time may convert into permanent haze that persists even at room temperature.
Gelatin addresses this problem by binding haze-forming particles and yeast cells and accelerating their sedimentation. It works best when added to cold beer, where flocculation is typically enhanced. Once settled, the clarified beer can be racked off, leaving the compacted sediment behind.
Unlike in winemaking, where gelatin targets specific polyphenol fractions, its practical effect in brewing is primarily the aggregation and rapid sedimentation of suspended particles. This makes it particularly useful for smaller-scale producers who want to achieve commercial-grade clarity without filtration.
It is worth noting that mainstream commercial breweries today rely more heavily on PVPP and silica gel for colloidal stabilisation.[6] Gelatin remains widely used in smaller-scale production and in applications where filtration is not available or desired.
Gelatin vs. Other Fining Agents
Among proteinaceous fining agents used in winemaking, gelatin occupies a specific niche. The AWRI comparison table places it first for tannin removal efficiency and first for colour removal, ahead of egg white, isinglass, and casein.[1] A 2023 study published in OENO One comparing four protein fining agents - casein, ovalbumin, and two gelatins - found that gelatins showed stronger interactions with high-tannin fractions than the other agents tested, with performance varying by gelatin type and molecular weight.[7]
Plant-based alternatives - pea protein, potato patatin, wheat gluten - are gaining traction in response to demand for vegan-friendly wines. A 2020 peer-reviewed study found that on Nebbiolo wine - characterised by a particularly complex phenolic composition - one pea-based fining agent achieved tannin reduction comparable to animal gelatin, while better preserving anthocyanins and colour intensity.[8] Results varied across wine varieties and doses, reflecting the context-dependent nature of plant protein fining.
For producers prioritising consistency, traceability, and a well-established regulatory track record, edible gelatin from certified manufacturers remains a widely used and well-established option.
Selecting the Right Gelatin for Winemaking and Brewing Applications
Gelatin is not a single product. Commercial offerings differ in bloom strength, molecular weight distribution, viscosity, and particle size - parameters that influence how the agent behaves in a specific wine or beer matrix. A gelatin that performs well on a tannic Nebbiolo may behave differently on a low-phenolic white wine or a hazy lager.
For production technologists, this means that sourcing decisions should go beyond price and availability. The supplier's ability to provide technical documentation, consistent batch specifications, and application support is what separates a commodity transaction from a working partnership.
Contact our team to discuss your specific application, request technical data sheets, or arrange a sample for bench trials.
Bibliography
[1] Australian Wine Research Institute (AWRI). Fining Agents. https://www.awri.com.au/industry_support/winemaking_resources/frequently_asked_questions/fining_agents/
[2] Xue, J. et al. Molecular Mechanisms and Applications of Polyphenol-Protein Complexes with Antioxidant Properties: A Review. PMC (2023). https://pmc.ncbi.nlm.nih.gov/articles/PMC10451665/
[3] Chen, W.L., Wang, M.L., Huang, C.M. Investigation of tannin-protein interactions in food systems: Implications for nutritional quality and functional food development. International Journal of Advanced Biochemistry Research, 9(12), 78-81 (2025). https://www.biochemjournal.com/archives/2025/vol9issue12/PartB/10-2-249-878.pdf
[4] Sarni-Manchado, P. et al. Analysis and Characterization of Wine Condensed Tannins Precipitated by Proteins Used as Fining Agent in Enology. American Journal of Enology and Viticulture, 50(1), 81-86 (1999). https://www.ajevonline.org/content/50/1/81.short
[5] WineMaker Magazine. Additives to Impact Phenolics and Tannins. https://winemakermag.com/article/additives-to-impact-phenolics-and-tannins
[6] Wang, Y., Ye, L. Haze in Beer: Its Formation and Alleviating Strategies, from a Protein-Polyphenol Complex Angle. Foods, 10(12), 3114 (2021). https://pmc.ncbi.nlm.nih.gov/articles/PMC8702196/
[7] Obreque-Slier, E., Cortés-Araya, K., Medel-Marabolí, M., López-Solís, R. Different effectiveness of protein fining agents when tested for interaction and precipitation with tannic acid, a seed polyphenol extract and seven wines. OENO One, 57(2) (2023). https://oeno-one.eu/article/view/7264
[8] Fia, G. et al. Phenolic Composition Influences the Effectiveness of Fining Agents in Vegan-Friendly Red Wine Production. PMC (2020). https://pmc.ncbi.nlm.nih.gov/articles/PMC6983225/
